麻豆传媒

Temporary loss of smell and taste was tied to COVID-19 infection in mildly symptomatic patients, but did not appear to persist a month after infection, a small survey of patients in Italy found.

Only 12% of mildly symptomatic COVID-19 patients reported persistent loss of smell and taste a month later, while the rest said their issues had either improved or resolved, reported Daniele Borsetto, MD, of Guy's and St. Thomas' Hospitals in London, and colleagues.

Previously, about two-thirds of this cohort who were being treated at home for COVID-19 infection said they had lost their sense of smell and taste, the authors wrote in .

Anosmia has emerged as one of the more unusual symptoms of COVID-19 infection, with anecdotal reports from Europe and the U.S. soon giving way to the CDC adding to their list of symptoms in screening for the virus.

While the percentage of patients with persistent loss of smell and taste appears small, by Joshua Levy, MD, of Emory University School of Medicine in Atlanta, projected those figures out to the U.S. population, estimating that more than 72,000 Americans could be presenting to clinicians with these symptoms.

"Presumably a portion of these patients will recover their sense of smell and taste in the next few months after infection, but there is no doubt we will see a considerable number seeking care for persistent symptoms," he wrote.

Borsetto and colleagues recently reported on the same cohort of 202 mildly symptomatic, home isolated patients, and 64% reported loss of taste or smell. This study was done to report on the progress of these patients, the authors said.

All 202 patients were contacted 4 weeks after they tested positive for COVID-19 via reverse transcription polymerase chain reaction, and interviewed about their symptoms. Tools to determine symptoms included the Acute Respiratory Tract Infection Questionnaire and the item about smell and taste. Patients were also asked to rate their impairment on a six-point Likert scale.

Of the original 202 patients, two died and 13 did not answer or refused the follow-up interview, so 187 patients were represented in the newest survey. More than half were women and the median age was 56. Interestingly, 60.4% reported smell or taste impairment in the 2 weeks before testing.

The authors also noted that of 74 patients not reporting altered smell or taste at baseline, 11 reported onsets of these symptoms, which bumped up "prevalence of smell or taste impairment" to 66.3%.

After 4 weeks, alteration of smell and taste was still prevalent in 69 patients, and was one of the most frequent symptoms reported at follow-up.

Overall, 55 patients reported complete resolution of smell or taste impairment, while 46 reported a decrease in severity, and 12 reported that the symptom was unchanged or worse. Among the 55 patients who recovered their sense of smell and taste, the median duration of smell and taste impairment was 11.2 days.

Interestingly, the SARS-CoV-2 swab test was repeated during the fourth week in 163 patients, and 52 still tested positive.

The authors also noted, "a higher severity of smell and taste impairment at baseline, reasonably due to a more severe injury of the olfactory neuroepithelium, was associated with a lower likelihood of recovery at 4 weeks."

Limitations to the data, the researchers said, include its self-reported nature, as well as the small sample size and that the study excluded patients with severe disease.

Levy turned his attention to treating these patients who may present with smell and taste impairments, saying he would recommend topical corticosteroids and olfactory training.

"Despite the lack of demonstrated efficacy for the use of topical corticosteroids for the treatment of postinfectious smell and taste dysfunction, there is evidence to support its use as a first-line treatment of these symptoms in the setting of chronic rhinosinusitis," he wrote, adding, "olfactory training is the only disease-specific intervention with demonstrated efficacy for the treatment of post infectious smell and taste disturbance."

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